This invention relates generally to pet foods and more particularly to senior pet foods.
Senior pets are typically well attended to so that the senior pet generally has a high quality, palatable and nutritionally balanced food which typically includes protein in the diet normally above about 26% by weight. Fortunately the advances of veterinary medicine and good nutrition benefits are available to senior pets so that such pets live longer. However, due to the normal biological aging processes, over time such pets continue to age, and lose an unacceptable portion of vital lean body mass. Such loss of lean body mass results in premature depletion of muscle and internal organs and can be irreversible. Older pets such as senior cats are more susceptible to such depletion than are younger cats. This undesired depletion is aggravated when inadequate protein is consumed by the senior cat in its diet, such as for example when the protein level in the diet of a senior cat is reduced and more pronounced when the dietary protein level drops below about 26% by weight.
Lean body mass plays a pivotal role in the biochemistry of a cat. Lean body mass exists as a reservoir within the body of the cat for protein turnover (proteins are constantly being broken down and new proteins produced). Lean body mass thus provides amino acids for the cat's synthesis of its life critical proteins such as immunoglobulin, hemoglobin, hormones and enzymes. Lean body mass provides nitrogen reserves to expend and so if there is a reduction in lean body mass, the feline has less nitrogen reserves to expend. Lean body mass is required for growth and maintenance of body tissues, including muscle and bone.
Reduced dietary protein is associated with diminution and loss of feline immune function. The immune system is the principal first line defense against the invasion of antigens into the feline body. Diminution and loss of immune function subjects the cat to the possibility of being unable to successfully defend against a body invasion of antigens, bacteria and viruses. Excessive loss of lean body mass is associated with undesirable high feline morbidity and mortality.